Energy independence is a modern priority driven both by anticipated climatic changes due to global warming and ever-increasing reliance on imported hydrocarbon derived energy sources. The need for renewable, clean and abundant energy sources is obvious from the likes of solar energy, especially from silicon photovoltaics (PVs), which is high on the list. A factor preventing the more rapid adoption of silicon PVs is their current high cost driven in part by limited supplies of the photovoltaic grade silicon (i.e., “Sipv”) used to manufacture monocrystalline or polycrystalline wafers.
Although silicon is the second most abundant element in the earth's surface, highly purified silicon needed to make PV cells is expensive because of the energy intensive, complex, and costly processes currently used in its manufacture. The large capital costs involved means that Sipv production takes years to ramp up. In 2006, the demand, by volume, for Sipv exceeded the demand for semiconductor or electronics grade silicon (i.e., “Sieg”) for the first time. The few companies manufacturing Sipv are currently unable to meet growing customer demand thereby reducing the potential for rapid growth in solar energy.
Many Sipv and Sieg manufacturers rely on what is known as the Siemens Si purification process (i.e., “the quartz rock purification process”) and modifications thereof. This process involves multiple steps starting from quartz rock and carbon sources to produce metallic metallurgical grade Si (i.e., “Simg”). Simg is further processed to produce corrosive, toxic, and potentially polluting chlorosilanes that are then subject to several high-energy steps to produce Sieg or Sipv.
Plasmas have been used to produce various materials, to adjust the surfaces of various materials, and for various test methods. Examples of these are described by:    1) F. Kail, A. Fontcuberta I Morral, A. Hadjadj, P. Roca I Cbarrocas, and A. Beorchia, “Hydrogen-plasma etching of hydrogenated amorphous silicon: a study by a combination of spectroscopic ellipsometry and trap-limited diffusion model”, Phil. Mag., Vol. 84, No. 6, 595-609, 21 Feb. 2004;    2) Q. Wang, C. Z. Gu, J. J. Li, Z. L. Wang, C. Y. Shi, P. Xu, K. Zhu, and Y. L. Liu, “Enhanced photoluminescence from porous silicon by hydrogen-plasma etching”, J. App. Phys., 97, 093501, 2005;    3) M. Dhamrin, N. H. Ghazali, M. S. Jeon, T. Saitoh, and K. Kamisako, “Hydrogen Plasma Etching Technique for Mono- and Multi-crystalline Silicon Wafers” 2006 IEEE World Conference on Photovoltaic Energy Conversion, Waikoloa, H A, May 2006; and    4) S. K. Singh, B. C. Mohanty, and S. Basu, “Synthesis of SiC from rice husk in a plasma reactor”, Bull. Mater. Sci. Vol 25, No. 6, pp 561-563, November, 2002;all of which are incorporated herein by reference.
Still, there remains a need in the art for alternative ways to produce high purity silicon materials, such as photovoltaic grade silicon metal and electronic grade silicon metal; and precursors thereof. For example there is a need for a process for producing a high purity silicon metal where the process is characterized as being simpler (e.g., requires fewer steps, such as fewer heating steps, uses one or more steps that are relatively fast; uses a relatively low processing temperature, or any combination thereof), more environmentally friendly, more energy efficient (e.g., at least 20 percent more energy efficient), or any combination thereof.